To convert Physical Damage to Cold Damage you can combine the Cold mastery with a special pair of Rare Gloves, or use Hrimsorrow Unique Gloves. For defenses, the build utilizes a medium-sized Life Pool, Life Leech, and around 20 to 40k of Armour. Occultist, among many other virtues, is very good at dealing short-range Cold Spell Damage, and so this skill suits this ascendancy perfectly.
Blade Vortex, due to being a Physical Spell, creates a great opportunity for a conversion build, as physical damage is the easiest one to convert. It can be linked to the Unleash Support Gem and cast 5 of them all at once, which is more than enough to map comfortably. Normally it would require you to stop and cast it a few times before reaching the threshold of usefulness and continue mapping, but not in this case. You can stack up this damaging effect up to 10 times, each time it grows in damage and size. These blades - vortexes, deal damage at such a rapid pace that they can be compared to a Spell version of Cyclone. Blade Vortex is one of the most popular Physical Spells in the game, it's a very basic skill that creates orbiting blades around the character.
